The research program in this application is concerned with the neural basis of social cognition. We propose to examine neocortical areas in and near the superior temporal sulcus (SIS), a region known for its ability to process the motion of living forms, integrate information from different sense modalities, and respond to agency and perspective taking. The STS region together with the amygdala, several parts of the frontal lobe, and other brain areas are thought to form a brain network dealing with social cognition. We propose to study the neural mechanisms of basic social cognition in humans and macaques by recording unisensory and multisensory responses elicited to social and non-social stimuli. We will study cross-species neural responses to visual, auditory and combined audiovisual stimulation. Apparent motion activation tasks depicting combined facial expressions and associated non-verbal vocalizations will be studied. We will use identical activation tasks to collect neurophysiological and neuroimaging data in human and macaque subjects. Event-related potential (ERP) recordings provide information with excellent time resolution - to millisecond precision, whereas neuroimaging techniques, such asfunctional magnetic resonance imaging (fMRI), provide accurate spatial information -to millimeter resolution. Combined fMRI and ERP measures in humans will provide an accurate picture of the brain circuits and temporal dynamics of social cognition. Under the identical experimental conditions, combined ERP and action potential recordings in macaques will identify the neuron populations and cellular processes indexed by the ERP measurements. Understanding how the healthy primate brain processes social information is important to understanding the biological bases for the social communication disorders (e.g. Asperger's syndrome, autism, schizophrenia), where severe impairments occur in reading social information from others. By using the same activation tasks and comparable methods in humans and monkeys we will be able to determine important similarities as well as differences in how the brain deals with relevant social information. Further, our multi-technique approach within each species will allow us to visualize where and when the brain activation manifests in the monkey and human brain.